1. Field of the Invention
This invention relates to a catalyst component for olefin polymerization which can give an olefin polymer, particularly an olefin copolymer in a high yield with a decreased amount of a by-product amorphous polymer, a process for producing the catalyst component, a catalyst for olefin polymerization, and a process for polymerizing olefins in the presence of the catalyst.
Olefin polymers, particularly olefin copolymers produced by using the catalyst component of the present invention have a low proportion of amorphous polymers. Films produced from these olefin polymers or copolymers, therefore, have excellent antiblocking property. As a result, the amount of an antiblocking agent such as silica can be decreased, and a film having excellent transparency can be obtained.
2. Description of the Prior Art
Many proposals have already been made on the method of producing a solid titanium catalyst component comprising magnesium, titanium, halogen and an electron donor as essential ingredients. It is known that the use of this solid titanium catalyst component in the polymerization of alpha-olefins having at least 3 carbon atoms can give highly stereoregular olefin polymers.
However, olefin copolymers obtained by using the solid titanium catalyst components so far proposed contain large amounts of by-product amorphous polymers, and film products prepared from these copolymers have the defect of being inferior in antiblocking property. This necessitated the incorporation of an antiblocking agent such as silica powder in the polymers, and the resulting films tend to have reduced transparency.